F3215-HP Load Balancing Module Load Balancing Configuration Guide-6PW101

2
NAT-mode Layer 4 server load balancing
Figure 1 Network diagram
NAT-mode Layer 4 server load balancing comprises the following elements:
• Cluster—A cluster that provides specific services, including an LB module and multiple servers.
• LB module—A device that distributes different service requests to multiple servers.
• Server—A server that responds to and processes different service requests.
• VSIP—Virtual Service IP address of the cluster, used for users to request services.
• Server IP—IP address of a server, used for an LB module to distribute service requests.
Figure 2 Work flow of NAT-mode Layer 4 server load balancing
NAT-mode Layer 4 server load balancing operates in the following way:
1. The host sends a request, using the host IP as the source IP and VSIP as the destination IP.